Multiple spindle indexing crankshaft lathe



Janyl3, 1942. w E GROENE T 2,269,908

MULTIPLE SPINDLE INDEXING CRANKSHAFT LATHE Filed Jan. 31, 1941 4Sheets-Sheet 1 PEI 'INVENTORS. WILLIAM EGROENE HAROtD J.5IEKMANN Jan.13,1942. W F, GROENE ETAL 2,269,908

MULTIPLE SPINDLE INDEXING CRANKSHAFT LATHE '5 mum :5.

Jan. 13,- 1942. w; F. GROENE ETAL MULTIPLE SPINDLE INDEXING CRANKSHAFTLATHE Filed Jan. 31, 1941 4 Sheets-She et 3 (I a as i s 17 w 5 LOADINGSTATION 8 o as I K; J 0 5 I 4' 4+ 0 a o "I Q as 8 w v a V o O I (D STA TTw 0 8 sa 0 +1 31 0 w 33 7 15 4a 43 STATION THREE 1 g\\\\\\\%\E\&\\\\\\\\\\\\\\\\\\\ I I-J g r I \INVENTORS. WILLIAM F.GROENE HAROLD J-SIEKNANN I Jan. 13, 1 w. F. GROENE EI'AL ,269,90

MULTIPLE SPINDLE INDEXING CRANKSHAFT LATHE Filed Jan. 31, 1941 4Sheets-Sheet 4 INDEX FITiY UNITED MULTIPLE SPIYDLE INDEXING CRANKSHAFTLATHE William F. Greene and Harold J. Siekmann, Cincinnati, Ohio,assignors to The R. K. Le Blond I Machine Tool Company, Cincinnati,Ohio, a corporation of Delaware Application January 31, 1941, Serial No.376,878

7 Claims. (Cl. 29-38) This invention pertains to certain improveated bythe movement of the indexing work ments in multiple spindle indexinglathes, and is spindles to effectthe return action of the cuttingParticularly related to such multiple spindle tools from fully fed inposition and then to bring crankshaft lathes of a type shown in Patentthese cutting tools to their fully retracted posi- Number 2,138,522,issued November 29, 1938, and tion after said delay period by thefurther inin copending application, Serial Number 332,540, dexing ofsaid work spindles to bring a new set filed April 30, 1940. Morespecifically, this inof work spindles to the work station, and then tovention pertains to the controlling of the movep i e m s whe by thefeeding mechanism ment of the cutting tools of such lathes inrelautomati ally re ains c n r of e c n tools tion to the indexingmovement of the machine in 10 to agai e h o fully d in position such away as to prevent damage and marring of dependent of the indexing motionof said work the Work by the cutting tools as they are retracted C ifrom the work after completing the machining Further features andadvantages of this inven- T FEICE operation on the work pieces in thevarious work ion will appear from thedetailed des r p of spindles. thedrawings in'which:

In machines of this multiple spindle indexing i u e I is a f agme tarydia View type, it has been found, that after the cutting o a p on of allsp d e d t p cra sha tools have been fully fed in to the Work and havelathe f a p shown in the above mentioned been held in dwell position,that in certain inat nt a d a pli at n shown p y in section n stances itis desirable to begin the indexing of the line I-I of Figures II andIII. the work spindles away from their respective F u I is a ri t d d eeva on of such work stations before the cutting tools are moved amultiple p d de l e s ow ng the back away from the Work so as to preventthis actuating mechanism f h s a ng tools M rearward motion of thecutting tools from m rvided at work station three for effecting thedering the previously turn d ork surface Espe layed returnaction ofthese shaving tools in relacially is this true when tools of the shavingor tion to theindexing of the work spindle carrier.

broaching type are used, because these types of Figure III is atransverse section through the tools are fed past the work piece so thatwhen machine 011 the e IIIIII of Figure they are fully fed int th work,their cutting Figure IV is an enlarged end view of the actuatedges areslightly beyond the work surface turned, s cam mounted on the indexingWork spindle with the r ult that h they are moved backcarrierdrum shownon the line IVIV of Figure wardly, without first indexing the work awayfrom actual cutting position, the returning cut- Figure V s an enla edfragmentar on o ting edge of these types of tools mar the Work in one oftha Cam slots of h Cam shown on the moving back to their retractedposition. v line f Figure V.

Itis therefore one of the chief objects of this Fi ure VI is a sim larenlarged fragmenta y invention to so control the tool movements and w Oanother Portion of One O the Ca s ots indexing mechanism of a lathe ofthis type in shown by t e line V V o u e V.

such a way that the indexing initially takes place 40 Figure VII is anenlarged dia V w so as to begin movement of the work away from sh w trelationship of e Shaving tool at actual cutting position when the toolsare in thethil'd work station with respect to the work fully fed inposition and then to later on, during surface being machined on a Workpiece at said the continuation of this indexing motion, con- Workstationindicated by the line VII-VII of tinue the rearward motion of the toolsback to Figure I. 4 their retracted position ready for the beginningFigure VIII is a fragmentary plan view of the of another cutting cycle.work and tool shown in Figure VII.

In certain other instances it is desirable to im- For purposes of anexemplary disclosure, this mediately retract the tools and index thework invention is shown applied to a four-spindle drum at some of thework stations while the tools at type crankshaft line bearing lathe of atype other of the work stations delay their retracting shown in theabove mentioned patent and apmovement until the indexing motion hasgotten plication. This machine comprises a base 1 upon under way. eachend of which is mounted the upright hous Another object of thisinvention is to provide, ings 2 and 3, which carry the indexing work ina multiple spindle indexing lathe, means operspindle carrier drum 4 uponwhich are mounted work spindles comprising the tailstocks 5 and 6 andthe center drive chuck housings 1 in which is suitably mounted centerdrive chucking mechanism 8, for example, of a type shown in Patent2,131,698, issued September 27, 1938. These center drive work spindlesmay be driven from the main drive spindle motor 9, through its motorpinion l and the gear I i carried on the main drive shaft [2 in a manneras fully disclosed in the above mentioned patent, so that these workspindles may all be driven during the turnin operation at the variousWork stations and may be stopped and started when the respective workspindle is brought into the loading station.

These various work stations comprising work station one, work stationtwo, and work station three, and also the loading station are arrangedas shown in Figure III. At work stations one and two are respectivelymounted the cutting tools l3 and I4, carried on their respective toolfeeding slides l5 and i6 and are actuated for radial to and from feedingwith respect to the work W in the work spindles presented at these workstations one and two by feeding mechanism as fully disclosed in theabove mentioned patent, which comprises suitable cam actuating mechanisml1 and I8 which is driven from the various feed shafts I9 and upon theouter ends of which are mounted the feed pinions 2|, as best seen inFigure II, in which pinion 2| is engaged by the segmental feed gear 22,appropriately journaled on the bearing surface 23, provided On theoutwardly projecting end of the indexing work carrier drum 4, as fullydisclosed in this mentioned patent, so that as the segmental gear 22 isrocked back and forth by means of the feed cylinder 24, Figure II,having a piston rod 25 which operates the floatingly reciprocatable rack26 in engagement with the segmental gear 22, these respective tools atwork stations one and two may be fed radially to and from the variouswork spindles presented at these work stations.

The relationship of the indexing of the work carrier 4 in relation tothe movement of the tools at work stations one and two is such thatafter the cutting tools at these work stations have finished their work,they are then automatically returned to fully retracted positionwhereupon the indexing of the work carrier then takes place in a mannerand by means of apparatus as fully set forth in the above mentionedpatent, so that these tools at work stations one and two are in fullyretracted positions before the indexing of the work carrier actuallytakes place.

At work station three is provided a series of special type of finishingtools known as shaving tools which have cutting edges angularly relatedto the axis of rotation of the work 28 and which cutting edges 21 feedtangentially of the work in a plane 29 indicated in Figure VII so thatwhen the tool feeds to the right, Figure VII, these shaving tools 30actually present their cutting edges 2'! beyond and away from contactwith the work piece at the time they are fully fed in toward the work.It has been found that in such types of tools, with the work stillrotating and in cutting position, that were the shaving tools 36retracted back again along the plane 29, that the respective edges 21would have a tendency to spring slightly back against the work and wouldcause a marring or scratching of the finished work surface. It istherefore, the chief object of this invention to so time the indexing ofthe work carrier 4 with respect to the withdrawal of the shaving tools36 that their cutting edges 21, after they have once been moved to fullyfed in position, do not begin to pass back over the tangentially feedingpath 29 to mar the work until the indexing motion of the work carrierhas gotten under way. This is accomplished by initially starting theindexing of the work carrier 4 and work spindles before permitting thetools 30 to move back in their retracting movement to the initialstarting position.

These shaving tools 30 are carried on appropriate tool blocks 3!, whichare fixed on the tool feeding slides 32 mounted on suitable dove tailguideways 33 in the frame 34 fixed to the mounting surface 35 formed onthe base I of the machine. Journaled in this frame 34, is the rock shaft36 having lever arms 31 fixed thereon which are connected by means ofsuitable pivot pins 38 to the blocks 39 which operate in appropriateslots 40, formed in these slides 32, so that rocking of the shaft 36effects sliding movement of the slides 32 to and from the work on theirrespective dove tail guideways 33. A compression spring 4i provided foreach of the slides 32, is carried in a bracket 42 fixed to each of theslides 32 and engage abutment blocks 43 fixed to the frame 34, as bestshown in Figure III, normally to urge the slide to withdrawn position sothat the feeding action effected in these slides by the shaft 36 isnormally opposed by these springs 4|.

The outer end of the rock shaft 36 is journaled in a suitable bearingbracket 44 fixed to the base I of the machine and has fixed on its outerend an actuating lever 45 which has a cam engaging roller 46 whichoperates against the surface 41a of the feed cam 41 fixed to thesegmental gear 22 by suitable screws 48, so that as the feed cylinder24, Figure II, actuates the segmental gear in infeeding motion to effectmovement of the tools at work stations one and two the surface 41a ofthe cam 41 engaging the roller 46 will automatically cause the toolslide 32 carrying the shaving tools 30, to be fed into the work alongthe plane of feeding 29, Figure VII, at the appropriate rate, so thatthe roller 46 moves relatively from the position 46a to the position 45.as shown diagrammatically in Figure II, thereby bringing these shavingtools 30 to the fully fed in position as shown in Figure VII when theroller has reached the point 46 as shown in Figure 11.

Having thus accomplished the infeeding of all of the cutting tools atwork stations one and two and the shaving tools at Work station three,appropriate control mechanism, as fully disclosed in the above mentionedpatent, then operates so that the cutting tools at work stations one andtwo are then fully retracted. Upon reaching their retracted position,indexing power is then applied to the work carrier 4 as disclosed in theabove mentioned patent, to initiate the indexing motion of the drum 4.

During the time of infeeding of the cutting tools 30, apparatus has beenset in position to prevent the immediate withdrawal of the cutting tools30 simultaneously with the return movement of the cutting tools at workstations one and two. This mechanism comprises a lever 49, which isfixed on a rock shaft 50, which rock shaft is appropriately journaled inan upright bracket 5| fixed to the base I of the machine, by suitablescrews 52 and also supported in a bracket 53. suitably mounted on thehousing 3 by appropriate screws 54 and which lever 49 is connected by asuitable link 55 with the lever 45. At the other end of the rock shaftis provided a downwardly extending lever 56, in which is carried aspring urged plunger 51, which is normally urged to the left of Figure Iby a suitable compression spring 58 to engage against the face 59 of adisc cam 60 comprising the segmental gib 60a and 60b appropriately fixedto the indexing work spindle carrying drum 4 by suitable screws 6! andpin 62, so that this cam 60 is carried around by the indexing motion ofthe drum 4.

On each of these segments 60a and 6%- are provided a series of cam slots63, one for each work spindle presented to the work station three, inthis case, there being four slots 63 since there are four work spindlesto be presented to work station three. When the cutting tools and theshaving tools at all the work stations are in fully fed in position, asshown in Figure II, the spring urged plunger 51 has a relative positionwith respect to a cam slot 63 in the disc cam 60 as shown at 51a inFigure IV, being entered into the slot 63 as shown in detail in FigureVI. After the cutting tools at work stations one and two have fullywithdrawn and set the indexing motion in operation, the relativemovement of the plunger 51 in the cam slot 63 as caused by the indexingmotion of the drum 4, causes the plunger 51 to move relatively from theposition 5111. to the position 511), during which portion of the camslot 63 the plunger 51 has no relative movement with respect to the axisof rotation 4a of the indexing work carrier 4, so that the tools on theslides 32 will be held in their fully fed in position even though theindexing motion has initially taken place and as a result, the roller 46on the lever 45 will be withheld away from contact with the surface 41aof the feed cam 41 on the segmental gear 22. However, upon furtherindexing of the work spindle carrier 4 after the work has initially beenmoved or indexed away from cutting position with respect to the tools39, these tools are then permitted to withdraw back to initial startingposition as the plunger 51 relatively moves from the position 51b asindicated in the Figure IV. At the point 510 the tools 30 are thus fullyretracted to their initial starting position and are again in propertimed relationship with the cutting tools at work stations one and two,the roller 46 on the lever 45 again being presented to the cam 41, asshown at 46a in Figure II. Further indexing however, of the work carrier4 to its final indexed position presenting another series of workspindles to the work stations causes the plunger 51 to move to therelative position 5111 at which point it arrives and remains so far ascircular movement about the cam 60 is concerned during the infeedingmotion of the various cutting tools to the work.

Having thus again brought the machine in condition for the next cuttingcycle, feed is again instituted by appropriately applying fluid pressureto the cylinder 24 causing the cutting tools at Work stations one andtwo to feed inwardly and likewise through the medium of the cam 41 andthe roller 46 of the lever 45, the feed of the shaving tools 30 thentakes place, it being noted distinctly that the plunger 51 has nowridden out of one of the cam slots 63 by proceeding upwardly on theangularly related surface 6311 Figure V on to the flat surface 59 of thecam 68 so that it is free to move radially on this surface with respectto the axis 4a of the work indexing carrier 4, so that as this gibtreating of the cutting tools 30 takes place, the plunger moves radiallyoutward on this face 59 of the 7 cam from the position 51d to theposition 51a again repeating, so that it can again initially drop intothe slot under the influence of the compression spring 58 and resume itspositionpreparatory to delayingthe return action of the shaving tools 30at the completion of the cutting cycle as described. I

We have thus provided an arrangement whereby a series of cutting toolsmay be fed into the work of a multiple spindle indexing machine in sucha manner that at the completion of the in feeding motion of the toolsindexing motion may be initially started before immediately returningthe cutting tools to their retracted position so as to avoid the returnof the cutting tools again over the work surface already machined,thereby preventing damage and marring of the machined work piece.Expressed another Way, we have provided in an indexing lathe, meanswhereby the cutting tool may be fed into the work and whereby the returnmotion of these cutting tools may be delayed during the initial motionof indexing of the work spindles away from the cutting tools beforeinstituting the withdrawal motion of the cutting tools so as to preventcutting edges of the tools from again passing over the work surfacespreviously machined by the infeeding motion of the tools.

Having thus fully set forth and described our invention what we claim asnew and desire to secure by United States Letters Patent is:

1. In a machine tool, an indexing work carrier, a work spindle on saidcarrier, indexing means for moving said carrier to present said workspindle to a work station of said machine tool, cutting tools at saidwork station, means independent of said indexing means for feeding saidcutting tools to said work spindle when at'said work station, and meanson said indexing work carrier for controlling the return motion of saidtools from said work spindle independent of said feeding means for saidcutting tools to delay the return motion of said tools until after saidindexing work spindle carrier has partially moved said work spindle awayfrom said work station.

2. In a multiple spindle lathe, a rotatable indexing work carrier, aseries of work spindles on said work carrier, means for indexing saidwork carrier to successively present each of said work spindles to awork station of said machine tool, cutting tools at said work station,means independent of said indexing means for feeding said cutting toolsto a work spindle when presented to said work station, and means on saidwork spindle carrier to effect withdrawal of said cutting tools from thework spindle at said work station as said carrier indexes a work spindleto the next work station. v

3. In a machine tool, a work spindle carrier, a plurality of workspindles mounted on said carrier, means for indexing said carrier so asto successively present said work spindles to a work station of saidmachine tool, cutting tools at said work station, means independent ofsaid indexing means for feeding said cutting tools to and from a workspindle when presented at said work station, and mean on said workspindle carrier effective when said carrier is indexed to cause delayedreturn of said tools from fully fed in position relative to said workspindle at said work station until the next work spindle has started onits way for presentation to said work station.

4. In a multiple spindle lathe, an indexing work spindle carrier, aplurality of work spindles mounted on said carrier, indexing means formoving said carrier to successively present said work spindles to aseries of work stations of said lathe, cutting tools at said workstations, means independent of said indexing means for feeding saidcutting tools to said work spindles when presented at said workstations, and means on said indexing work carrier independent of saidfeeding means for controlling the return motion of said cutting tools.

5. In a multiple spindle indexing machine tool, a work spindle carrier,a series of work spindles mounted on said carrier, means for indexingsaid carrier so as to successively present a series of work spindles toa series of work stations of said machine tool, cutting tools at saidwork stations, means independent of said indexing means for feeding saidcutting tools to said work spindles when presented at said workstations, and means on said work spindle carrier independent of saidfeeding means for returning some of the cutting tools at some of saidwork stations after said work spindle carrier has begun a partialindexing movement in presenting the next series of work spindles to saidwork stations.

6. In a multiple spindle indexing machine tool, a work spindle carrier,a series of work spindles mounted on said carrier, means for indexingsaid carrier so as to successively present said work spindles to aseries of work stations of said machine tool, cutting tools arranged ateach of said work stations, common means independent of said indexingmeans for feeding all of said cutting tools to said work spindles whenat said work stations, said means also serving to withdraw some of saidtools to retracted position away from said work spindles, and means onsaid work spindle carrier independent of said feeding means forcontrolling the return motion of some of said cutting tools by theindexing movement of said carrier.

7. In a multiple spindle indexing machine tool, a work spindle carrier,a series of work spindles mounted on said carrier, means for indexingsaid carrier so as to successively present said work spindles to aseries of work stations of said machine tool, cutting tools at each ofsaid Work stations, common means independent of said indexing means forfeeding all of said cutting tools to said work spindles when at saidwork stations, said means also serving to withdraw some of said tools toretracted position away from said work spindles, means independent ofsaid feeding means on said work spindle carrier operatively connected tosome of the tools at some of said work stations whereby rotation of saidwork spindle carrier effects delayed return motion of some of thesecutting tools with respect to the work spindles while said work spindlesare being initially indexed away from cutting position for presentationof a new series of work spindles to said work stations.

WILLIAM F. GROENE. HAROLD J. SIEKMANN.

